A 5.7 magnitude earthquake rocked southeastern Alaska, about 73km from Haines, near Glacier Bay National Park and Preserve.The earthquake hit on Wednesday at 11:58 GMT southwest of Haines, which has a population of over 2,500 people. The epicenter was 10km deep, according to United States Geological Survey.The quake was first reported at a magnitude of 5.8, however it was subseqently downgraded to 5.7.There have been no reports of casualties.The circum-Pacific seismic belt, the earth's most active seismic feature, brushes Alaska and the Aleutian Islands, resulting in frequent earthquakes. More than 80 percent of the planet's tremors occur in the circum-Pacific belt, according to USGS data.